Hi Ahmed,

You need an ocaeanic environment to form the limestone before volcanic activities took place and followed by a continental condition favorable for oxidation where the red beds could form. Interesting, isn't it?

Good luck! 

yes interesting so the tectonic setting may be a continental margin , and the cause of such igneous and oxidizing events may is a subduction of another plate beneath that of the contiental margin , Right ?

Hi Ahmend,

This kind of circumstance may be back-arc tectonic setting in active continental margin

Volcanic rocks and red beds generally involve punctuated volcanic activity and either the development of soil profiles or in some cases the input of easily oxidized ash, palaeo-climate is also very important. There is no requirement for subduction, these features are extrememly common on rifted margins both in the form of continental flood basalts and more localized volccanism on magma poor margins. The chemistry of the volcanic rocks can give good insights into the tectonic setting.... and the literature depending on where in the world you are looking at!

yes it seems its looking good thank you both john and Songabi and yes how did i forgot that the area is in Peru where Andes arc volcanism is present :)

thanks 

Hi Ahmed

Close to Peru in Ecuador, we have same volcanic arc + red beds over limestones of Late Jurassic. However, there a regional disconformity above the limestones. May be are the same formations or lateral equivalent?